1. Field of the Invention
The present invention relates to: a printing system having an information processing apparatus such as a personal computer and a printing apparatus such as a multi-function peripheral (MFP), i.e., a multifunctional digital machine, both of which are capable of being connected to each other through a network; and a printing apparatus to be employed in the printing system.
2. Description of the Related Art
The following description sets forth the inventor's knowledge of related art and problems therein and should not be construed as an admission of knowledge in the prior art.
There has been a printing apparatus such as an MFP as described above, having a main CPU that controls an engine including a fuser and all the other portions of the printing apparatus. In order to achieve less power consumption, the printing apparatus supports power saving mode such as what is called “deep sleep mode”, by which power to the main CPU as well as to the engine is shut down.
Without power, the main CPU cannot recognize a print job received through the network, for example from a user terminal.
As a solution to such a problem, there has been a printing apparatus further having a sub CPU that receives power and works even in deep sleep mode and consumes less power than a main CPU.
The printing apparatus having the sub CPU receives a connection request packet such as a print job packet from the network while deep sleep mode is ON. Subsequently, the sub CPU returns a proxy response to activate the main CPU and its peripheral circuitry then transfers the received packet to the main CPU. The main CPU judges that it is a print job packet after analyzing the packet and activates the fuser and others by delivering power to the engine and others from the power supply portion. The main CPU then executes a print job.
The printing apparatus having the main CPU and the sub CPU has the following problem: it takes time for the main CPU to prepare for activating the engine because the main CPU needs to have been activated by the sub CPU that received a packet then judged that it was a print job packet, as described above. More specifically, a fuser in the engine requires a certain amount of heating time to reach an appropriate temperature, thus a slow activation of the fuser eventually retards the times for starting and finishing the print job.
The main CPU can be configured to activate the engine prior to judging that the receive packet is a print job, which could lead to a waste of power consumption because the engine may be activated for a non-print job.
Japanese Unexamined Patent Publication No. 2011-037126 discloses a power save controller device that allows a quicker preparation for image forming than in the case where power saving condition is cancelled after an instruction for image forming is given. The power save controller device comprises: a receiver that receives information objects from an external apparatus through a communication line; a memory that stores a specific information object other than an instruction information object related to instructions for image forming, the specific information object having being received by the receiver within a predetermined time period until the instruction information is received by the receiver; and a controller that cancels power saving condition in the case where both the following conditions are satisfied: (1) a main controller in need of power saving is in power saving condition, consuming less power than in normal condition; and (2) an information object received by the receiver matches the specific information object stored on the memory.
Japanese Unexamined Patent Publication No. 2010-288225 discloses a data processing apparatus that performs responding appropriately depending on the condition of receiving a packet through a network while achieving less power consumption. The data processing apparatus comprises a packet processor that transmits a reply data object to a source of a received packet if the received packet has a proxy response pattern, the reply data object corresponding to the proxy response pattern and updates judgment information if the condition of receiving a packet having a possible proxy response pattern is a specific one, the judgment information being stored on a memory such that the packet having the possible proxy response pattern is identified as having the proxy response pattern.
According to the technique as described in Japanese Unexamined Patent Publication No. 2011-037126, when a SNMP description is received it is judged whether or not it has a source IP address and an object identifier (OID) having ever been received; if it has a source IP address and an OID having ever been received, it seems most likely that a printer driver has just been activated to prepare for a print job to be received soon, thus sleep mode is turned OFF prior to receipt of it.
The technique has a problem that a print job may not always be received soon and sleep mode may be turned OFF long prior to receipt of it, which would lead to a waste of power consumption. Furthermore it is inconvenient that only an information processing apparatus having ever given instructions for printing can take advantage of the technique.
According to the technique as described in Japanese Unexamined Patent Publication No. 2010-288225, a packet having a possible proxy response pattern can be changed depending on the condition of receiving it while a quicker preparation for printing back from sleep mode cannot be achieved.
The description above can be summarized as follows: (1) it takes time for a conventional printing apparatus having a sub CPU to start printing because it takes time for its engine including a fuser to recover from power saving mode, which has so far been an unsolved problem; and (2) the main CPU can be configured to activate the engine prior to judging whether or not the received packet is a print job, which could lead to a waste of power consumption because the engine may be activated for a non-print job. Japanese Unexamined Patent Publications No. 2011-037126 and No. 2010-288225 did not solve these problems.
The description herein of advantages and disadvantages of various features, embodiments, methods, and apparatus disclosed in other publications is in no way intended to limit the present invention. Indeed, certain features of the invention may be capable of overcoming certain disadvantages, while still retaining some or all of the features, embodiments, methods, and apparatus disclosed therein.